JP4898587B2 - Heat pump water heater - Google Patents

Description

  The present invention relates to a heat pump water heater, and is particularly suitable for a heat pump water heater that performs a tank boiling back operation.

  A conventional heat pump water heater has a large-capacity hot water storage tank similar to an electric water heater, operates a heat pump using cheap discount electricity at night, boils hot water at night, and stores it in the hot water storage tank. A hot water storage type in which the stored hot water is used during the day is common. As an example of this hot water storage type heat pump water heater, one shown in Japanese Patent Application Laid-Open No. 2003-156254 (Patent Document 1) can be cited.

  The heat pump water heater of Patent Document 1 is a hot water storage type having a 370 L large-capacity hot water storage tank, and basically performs a tank boiling back operation once a day at night.

  In the boil-back control, when the amount of hot water used per day is 250L or more, the entire amount of 370L is boiled back, and when the remaining hot water amount becomes 150L or less, boil-back is performed and the amount of hot water used per day is less than 250L. In this case, 250 L is boiled back, and then boil-back is performed when the amount of remaining hot water becomes 75 L or less. Moreover, about the boil-back temperature, although only the example of 90 degreeC is described, generally it is set as 90 degreeC in winter corresponding to outside temperature, and boil-back is performed at 65 degreeC in other periods. .

  On the other hand, in recent years, instantaneous heat pump water heaters have been developed in which a hot water tank is directly operated to supply hot water heated directly during the daytime when hot water is used, thereby greatly reducing the size of the hot water storage tank. As an example of this instantaneous heat pump water heater, one disclosed in Japanese Patent Application Laid-Open No. 2003-279133 (Patent Document 2) can be cited.

  In the heat pump water heater of Patent Document 2, hot water storage operation is performed in advance, and hot water (60 ° C. or higher) is stored in a 60 to 100 L small hot water storage tank. When using hot water, the heating temperature by the heat pump circuit does not reach the appropriate temperature (42 ° C). At the beginning of operation, hot water from the hot water storage tank is mixed with the heating water by the heat pump circuit to supply hot water to the user terminal as the appropriate temperature, and the heating temperature by the heat pump circuit When the temperature reaches a predetermined temperature, the hot water supply from the hot water storage tank is stopped, and the appropriate temperature water heated by the heat pump circuit is directly supplied to the use side terminal for use.

When the remaining amount of hot water in the hot water storage tank decreases (the hot water temperature decreases) in a state where the user terminal is not used, the tank boiling back operation is performed. In this tank boiling back operation, the heat pump circuit is operated, the heating temperature is raised to a predetermined temperature, the in-machine circulation pump is operated, and the water accumulated in the lower part of the hot water storage tank is heated by the heat pump circuit to generate high-temperature water. Return to the top of the hot water storage tank and refill the hot water storage tank with hot water.

JP 2003-156254 A JP 2003-279133 A

  Generally, the operating efficiency of heat pump operation (that is, coefficient of performance (COP)) is that the lower the heating temperature, the lower the compressor speed and the less mechanical loss. The coefficient (COP) can be improved. In addition, the smaller the amount of hot water stored in the hot water storage tank, the smaller the amount of heat released, and the more energy can be saved. Furthermore, the lower the hot water storage temperature of the hot water storage tank, the smaller the amount of heat dissipation, and the power can be saved.

  However, the above-described hot water storage heat pump water heater of Patent Document 1 is a control that performs tank boiling back operation once a day at night, and uses a large hot water storage tank to increase the amount of boiling back and raise the boiling temperature. There is a need. For this reason, the amount of heat radiation from the hot water storage tank is increased and energy efficiency is lowered, and the hot water heater is large and heavy, which causes a problem in installation.

  Moreover, in the instantaneous heat pump water heater of Patent Document 2 described above, the number of times of tank boiling back operation is not considered. In other words, since the heat pump circuit requires a rise time of several minutes for the heating temperature to reach an appropriate temperature, it is particularly important to minimize the number of times the tank is boiled back in the daytime from the viewpoint of power saving and power charge. However, in the heat pump water heater of Patent Document 2, the optimum operation control for this point has not been achieved.

  In addition, fine power saving control is required to cope with various differences such as differences in hot water usage due to differences in family composition and changes in hot water usage due to seasonal changes. This was not the optimal operation control for this point.

  The object of the present invention is to easily carry out fine tank boiling back corresponding to diversification of hot water usage, optimize the tank boiling back amount and temperature, minimize the number of tank boiling back, etc. It is in providing the heat pump water heater which can plan.

The first aspect of the present invention for achieving the above-described object includes a compressor that compresses a refrigerant, a first heat exchanger that exchanges heat between the refrigerant discharged from the compressor and water, and the first heat exchanger. A decompression device for decompressing the refrigerant from the heat exchanger, a second heat exchanger provided between the decompression device and the compressor, a hot water storage tank for storing water warmed by the first heat exchanger, A hot water storage circuit for returning water in the hot water storage tank to the hot water storage tank via the first heat exchanger, a tank hot water supply circuit for supplying hot water in the hot water storage tank to a use terminal, and a tank boiling back operation by the hot water storage circuit In the heat pump water heater provided with control means for performing control so as to perform, the control means increases the boil-back heat amount and performs the tank boil-back operation when the tank boil-back operation reaches a predetermined number of times. To control Located in.

Moreover, the 2nd aspect of this invention is the refrigerant | coolant from this compressor which compresses a refrigerant | coolant, the 1st heat exchanger which heat-exchanges the refrigerant | coolant discharged from this compressor, and water, and this 1st heat exchanger. , A second heat exchanger provided between the decompressor and the compressor, a hot water storage tank for storing water warmed by the first heat exchanger, and water in the hot water storage tank A hot water storage circuit that returns the hot water in the hot water storage tank to the hot water storage tank via the first heat exchanger, a tank hot water supply circuit that supplies hot water in the hot water storage tank to a use terminal, and a tank boiling back operation by the hot water storage circuit during night time And a heat pump water heater provided with a control means for performing control so as to perform the tank boiling back operation even outside the night time zone as necessary, the control means includes the boiling back amount of the hot water storage tank and the hot water storage tank. Boil back temperature Setting a plurality of tanks boiling return heat combined, the tank water heating return times back boiling was operated except nighttime is increasing the boiling back heat if it becomes a predetermined number of times, return to boil and this change There is a control to perform the tank boiling back operation in the night time zone based on the amount of heat .

A more preferable specific configuration example in the second aspect of the present invention is as follows.
(1) wherein, with increasing number of times that the tank water heating return operation other than band the night time, the increase in favor of boiling return amount of the boiling return heat, boiling of the water heating return heat When the return amount reaches a predetermined amount, the boil-back temperature of the boil-back heat amount is increased.
(2) The control means performs control so as to forcibly perform the tank boiling back operation once a day during the night time zone, and the number of tank boiling back operations outside the night time zone has reached a predetermined number or more. Increase the amount of boil-back heat .
(3) The control means divides the time zone other than the night time zone into a peak time zone and other time zones, sets the number of boilback times in the peak time zone as n, and boilback times in the other time zones. Is set to m, and when the number of times of re-boiling other than the night time zone is (n + m) ≧ 1, the boil-off heat amount of the tank boil-back operation in the next night time zone is changed to the previous boil-back heat amount (n × 2 + m) Raise to a level with
(4) Control is performed to forcibly perform the tank boiling back operation once a day during the night time zone, and the state where the amount of remaining hot water in the tank boiling back operation during the night time zone is equal to or greater than a predetermined amount If it continues, reduce the tank boil-back heat quantity of the tank boil-back operation in the next night time zone.
(5) The control means divides the time zone other than the night time zone into a peak time zone and other time zones, sets the number of boilback times in the peak time zone to n, and boilback times in the other time zones. Is set to m, and when the number of times of reheating other than the night time zone is (n + m) = 0 and the amount of remaining hot water in the tank at the time of tank reheating operation is greater than or equal to a predetermined number of times When it is continuous, the tank boil-back heat quantity in the tank boil-back operation in the next night time zone is lowered by one level.

Moreover, the 3rd aspect of this invention is the refrigerant | coolant from this compressor which compresses a refrigerant | coolant, the 1st heat exchanger which heat-exchanges the refrigerant | coolant discharged from this compressor, and water, and this 1st heat exchanger. , A second heat exchanger provided between the decompressor and the compressor, a hot water storage tank for storing water warmed by the first heat exchanger, and water in the hot water storage tank A hot water storage circuit for returning water to the hot water storage tank via the first heat exchanger, a direct hot water supply circuit for directly supplying hot water heated by the first heat exchanger to a use terminal, and hot water in the hot water storage tank A tank hot water supply circuit to be supplied to the terminal, and a control means for performing a tank boiling back operation by the hot water storage circuit during the night time zone and controlling the tank boiling back operation outside the night time zone as necessary. In a heat pump water heater , The control means, the number of the sets of boiling return amount and a plurality of tanks boiling return heat quantity boiling returned combining the temperature of the hot water storage tank of the hot water storage tank, return boiling was tank boiling return operation other than band the night time Is to increase the boiling-back heat amount when the number of times reaches the predetermined number of times, and control to perform the tank boiling-back operation in the night time zone based on the changed boiling-back heat amount .

A more preferable specific configuration example in the third aspect of the present invention is as follows.
(1) The control means performs control so that hot water is supplied to a use terminal by using both a direct hot water supply circuit and a tank hot water supply circuit at the start of operation of the heat pump circuit.

  According to the heat pump water heater of the present invention, it is possible to easily perform fine tank boiling back corresponding to diversification of the amount of hot water used, optimize the tank boiling back amount and temperature, and minimize the number of times of tank boiling back. This can save power.

  Hereinafter, a heat pump water heater according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3.

  First, the entire heat pump water heater of this embodiment will be described with reference to FIG. FIG. 1 is an overall configuration diagram of the heat pump water heater of this embodiment.

  The heat pump water heater includes a heat pump circuit 30, a hot water supply circuit 40, and an operation control means 50. The operation control means 50 is constituted by a microcomputer.

  The heat pump circuit 30 is configured by a two-cycle system including a first refrigerant circuit 30a and a second refrigerant circuit 30b, and is disposed in the compressors 1a and 1b and the water refrigerant heat exchanger (first heat exchanger) 2. 2a, 2b, decompression devices 3a, 3b, and air refrigerant heat exchangers (second heat exchangers) 4a, 4b are connected in sequence through refrigerant pipes, and the refrigerant is sealed in them. Yes.

  The compressors 1a and 1b that compress the refrigerant to a high temperature and a high pressure are capable of capacity control, and are operated with a large capacity when supplying a large amount of hot water. Here, the compressors 1a and 1b can be controlled at a rotational speed from a low speed (eg, 700 rpm) to a high speed (eg, 7000 rpm) by PWM control, voltage control (eg, PAM control), and a combination control thereof. It has become.

  The water refrigerant heat exchanger 2 includes refrigerant side heat transfer tubes 2a and 2b and water supply side heat transfer tubes 2c and 2d, and performs heat exchange between the refrigerant side heat transfer tubes 2a and 2b and the water supply side heat transfer tubes 2c and 2d. It is configured as follows.

  In general, an electric expansion valve is used as the decompression devices 3a and 3b, and the medium temperature and high pressure refrigerant sent through the water refrigerant heat exchanger 2 is decompressed and sent to the air refrigerant heat exchangers 4a and 4b as a low pressure refrigerant that easily evaporates. . Further, the decompression devices 3a and 3b function to adjust the refrigerant circulation amount in the heat pump circuit by changing the throttle amount of the refrigerant passage, or to fully open the throttle amount to bring the medium temperature refrigerant into the air refrigerant heat exchangers 4a and 4b. It also serves as a defroster that sends frost to melt.

  The air refrigerant heat exchangers 4a and 4b take in outside air by the rotation of the blower fans 5a and 5b, exchange heat between the air and the refrigerant, and absorb heat from the outside air.

  The hot water supply circuit 40 includes a water circulation circuit for performing hot water storage, direct hot water tank hot water supply, bath hot water filling, and bath reheating.

  The hot water storage circuit for storing hot water is a water circuit for storing high-temperature water in the hot water storage tank 16 by the tank boiling back operation. The hot water storage tank 16, the in-machine circulation pump 17, the flow sensor 10 for the water refrigerant heat exchanger, and the water supply side heat transfer pipe 2c. 2d, the hot water supply mixing valve 11, and the hot water storage tank 16 are connected in sequence through a water pipe.

  The direct hot water supply circuit that performs direct hot water supply includes a water supply connection port 6, a pressure reducing valve 7, a water supply water amount sensor 8, a water supply side check valve 9, a water refrigerant heat exchanger flow rate sensor 10, water supply side heat transfer tubes 2 c and 2 d, and hot water supply mixing. The valve 11, the hot and cold water mixing valve 12, the flow rate adjusting valve 13, and the kitchen outlet connection port 14 are sequentially connected through a water pipe. The water supply connection port 6 is connected to a water supply source such as water supply, and the kitchen hot water connection port 14 is connected to a use side terminal such as a kitchen faucet 15.

  A tank hot water supply circuit that performs tank hot water supply includes a water supply connection port 6, a pressure reducing valve 7, a water supply amount sensor 8, a water supply side check valve 9, a hot water storage tank 16, a hot water supply mixing valve 11, a hot water mixing valve 12, a flow rate adjustment valve 13, The kitchen outlet connection port 14 is sequentially connected through a water pipe.

The bath hot water filling circuit for performing bath hot water filling includes a water supply connection port 6, a pressure reducing valve 7, a water supply water amount sensor 8, a water supply side check valve 9, a water refrigerant heat exchanger flow rate sensor 10, water supply side heat transfer tubes 2 c and 2 d, Hot water mixing valve 11, hot water mixing valve 12, flow rate adjustment valve 13, bath pouring valve 18, flow switch 19, bath circulation pump 20, water level sensor 21, bath inlet / outlet hot water connection port 22, bath circulation adapter 23 1 , bathtub 24 It is configured by sequentially connecting through water pipes. Further, the bath inlet / outlet connection port 22 is connected to the bath faucet 27 and a shower (not shown) together with the bathtub 24 so as to supply hot water.

  During bath hot water filling, hot water supply from the hot water storage tank 16 to the bathtub 24 is performed in a range where the amount of hot water in the hot water storage tank 16 does not fall below the minimum required amount, together with direct hot water supply by the bath hot water filling circuit.

The bath remedy circuit for bath preparation is the bath water transfer of the bathtub 24, bath circulation adapter 23 1 , bath inlet / outlet connection port 22, water level sensor 21, bath circulation pump 20, flow switch 19 and bath heat exchanger 23. A heat pipe 23b, a bath outlet connection port 26, a bath circulation adapter 23 1 , and a bathtub 24 are sequentially connected via a water pipe.

  At the time of bathing, hot water heated by the water / refrigerant heat exchanger 2 by operating the heat pump circuit and the in-machine circulation pump 17 and opening the hot water on-off valve 25 together with the water circulation of the bath water by the bath chasing circuit. Is circulated through a hot water heat transfer tube 23a provided in the bath heat exchanger 23, heat is exchanged between the hot water heat transfer tube 23a and the bath water heat transfer tube 23b, and the bath is reheated.

The operation control means 50 performs operation / stop of the heat pump circuit 30 and rotation speed control of the compressors 1a and 1b based on the operation settings of the kitchen remote controller 51 and the bath remote controller 52, and the refrigerant throttle amounts of the decompression devices 3a and 3b. adjustment, flight circulating pump 17, the operation-stop and hot water supply mixing valve 11 of the bath circulation pump 20, the hot and cold water mixing valve 12, flow control valve 13, a bath hot-water pouring valve 18, by the control of the hot water off valve 25, the hot water storage operation , Direct hot water supply operation, tank hot water supply operation, bath hot water operation, bath memorial operation.

  The operation control means 50 controls the rotation speed of the compressors 1a and 1b, and immediately after the start of operation, the operation control means 50 operates at a predetermined high speed rotation speed in order to shorten the heating start-up time. At the time of operation, etc., control is performed so as to operate at a low speed corresponding to the heating temperature.

  Further, the operation control means 50 sets three or more tank boiling back levels combining the boiling back amount and the boiling back temperature of the hot water storage tank 16, and changes the tank boiling back level depending on the number of tank boiling back times. It has a control means.

  In the heat pump water heater, in addition to a plurality of tank thermistors 16a to 16e for detecting the hot water storage temperature and the amount of hot water stored in the hot water storage tank 16, thermistors (not shown) for detecting the temperature of each part and compressors 1a and 1b A pressure sensor (not shown) for detecting the discharge pressure, a water level sensor 21 for detecting the water level in the bathtub 24, and the like are provided. Each detection signal is input to the operation control means 50. The operation control means 50 controls each device based on these signals. Note that a plurality of tank thermistors 16 a to 16 e are installed at intervals across the upper and lower sides of the hot water storage tank 16.

Hot water supply mixing valve 11, in the hot-water supply operation beginning, between the water refrigerant heat exchanger 2 side and the hot and cold water mixing valve 12 side, and between the hot water storage tank 16 side and the hot and cold water mixing valve 12 side are both open, Hot water is supplied from both the water-refrigerant heat exchanger 2 and the hot water storage tank 16. When the heating temperature in the water refrigerant heat exchanger 2 by the heat pump circuit 30 reaches the hot water supply temperature (about 42 ° C.), the hot water supply mixing valve 11 is closed between the hot water storage tank 16 side and the hot water mixing valve 12 side, and the water refrigerant Hot water is supplied only from the heat exchanger 2.

  The hot water on-off valve 25 is provided between the water-refrigerant heat exchanger 2 and the bath heat exchanger 23. The hot-water on-off valve 25 is opened when the bath is replenished to perform the bath reheating operation, and is closed at other times. The leakage of heat from the exchanger 2 to the bath heat exchanger 23 is prevented.

  The water supply side check valve 9 allows water to flow only in one direction and prevents backflow from the hot water storage tank 16, the water / refrigerant heat exchanger 2, and the bath heat exchanger 23.

  Next, the operation of the heat pump water heater of this embodiment will be described with reference to FIG. FIG. 2 is a flowchart showing a hot water supply operation and a subsequent tank boiling back operation when the kitchen faucet 15 of the heat pump water heater of FIG. 1 is opened and hot water is used. These operations are controlled by the control means 50.

  When the kitchen faucet 15 is opened and the use of hot water is started in a time zone other than the night time zone (step 61), the operation control means 50 activates the compressors 1a and 1b to start the operation of the heat pump circuit 30 and connects to the water supply. Port 6, pressure reducing valve 7, water supply water amount sensor 8, water supply side check valve 9, water refrigerant heat exchanger flow sensor 10, water supply side heat transfer pipes 2 c and 2 d, hot water supply mixing valve 11, hot water mixing valve 12, flow rate adjustment valve 13. The direct hot water supply operation by the direct hot water supply circuit of the kitchen outlet 14 and the kitchen faucet 15 is started (step 62). At the same time, water supply connection port 6, pressure reducing valve 7, water supply water amount sensor 8, water supply side check valve 9, hot water storage tank 16, hot water supply mixing valve 11, hot water mixing valve 12, flow rate adjustment valve 13, kitchen outlet connection port 14, kitchen faucet The tank hot water supply operation by 15 tank hot water supply circuits is started (step 63).

  Here, the heat pump circuit 30 sends the high-temperature and high-pressure refrigerant compressed by the compressors 1a and 1b to the refrigerant-side heat transfer tubes 2a and 2b of the water-refrigerant heat exchanger 2, and the water flowing through the water supply-side heat transfer tubes 2c and 2d. It heats and flows out to the hot water supply mixing valve 11 side. However, at the time of start-up immediately after operation, the refrigerant sent to the water-refrigerant heat exchanger 2 is not sufficiently high-temperature and high-pressure, the temperature is low, and the water-refrigerant heat exchanger 2 as a whole is cooled. The heating capacity to do is not enough. As the time elapses, the refrigerant becomes high temperature and pressure, and accordingly, the amount of heat released from the generated refrigerant increases, and the ability to heat water increases. It takes several minutes for the heating capacity of the heat pump operation to reach an appropriate temperature. For this reason, the operation control means 50 makes the rotation speed of the compressors 1a, 1b higher than usual from the start of operation until it reaches an appropriate temperature state, and supplies the hot water from the hot water storage tank 16 with a tank hot water supply operation ( Step 63) is performed in parallel, and the kitchen faucet 15 is controlled to supply hot water of appropriate temperature.

  During the direct hot water supply operation, the heating temperature of the heat pump circuit 30 is determined (step 64), and if the temperature is lower than the predetermined temperature, the parallel hot water supply operation and the tank hot water supply operation are continued. If the temperature determination in step 64 reaches a predetermined temperature or higher, the tank hot water supply operation is stopped (step 65), and the hot water supply by direct operation of direct hot water supply is continued (step 66).

  The operation control means 50 operates the hot water mixing valve 11 to increase the tank hot water supply amount when the mixed hot water temperature after the hot water mixing valve 11 is lower than the appropriate temperature, and to decrease the tank hot water supply amount when the mixed hot water temperature is higher than the appropriate temperature. Adjust the flow rate ratio to obtain the appropriate temperature. Furthermore, the hot water supply temperature to the terminal in use can be adjusted by adjusting the amount of water supplied from the hot water / mixing valve 12.

  The role of the hot water storage tank 16 is to supplement the heating capacity of the heat pump circuit 30 until it reaches a temperature sufficient for the hot water supply temperature, and the capacity of the heat pump circuit 30, particularly the outputs of the compressors 1a and 1b are large. The startup time can be shortened and the hot water storage tank 16 can be made smaller.

  Moreover, in order to respond | correspond to simultaneous use of several places only by direct hot water supply, such as when performing bathing hot water at the same time as kitchen hot water supply, the two-cycle heat pump circuits 30a, 30b using two compressors 1a, 1b are used. However, if the capacity of the compressor is sufficient, the present invention can be applied to a one-cycle heat pump circuit.

  Next, when the faucet is closed and the use of hot water is completed (step 67), the direct hot water supply operation is stopped if only the direct hot water supply operation is performed (step 68). When the faucet in the case where the tank hot water supply operation and the direct hot water supply operation are used immediately after the hot water is used is closed and the use of the hot water is finished, both the direct hot water supply operation and the tank hot water supply operation are stopped.

  After the hot water supply operation is stopped, the tank thermistors 16a to 16e detect the hot water storage temperature and the hot water storage amount, and the remaining tank hot water amount is determined based on the detection results (step 69). Therefore, the amount of remaining hot water in the tank is a concept including the temperature and amount of the remaining hot water.

In the determination of step 69, when the tank remaining hot water is on a given Ne以 does not perform the hot water storage operation, waits for a use of use the terminal.

  If the determination in step 69 is less than the predetermined value, the tank boiling-back operation is started (step 70), and the determination of the tank remaining hot water amount is continued (step 71). When the amount of remaining hot water in the tank exceeds a predetermined value, the heat pump circuit is stopped and the tank boiling back operation is ended (step 72).

  When the use of hot water supply during the day is finished and the night time zone is reached (step 73), the tank boiling back level is determined based on the number of times of tank boiling back (step 74). This night time zone is a time zone during which electricity charges are discounted. The tank boiling back level is updated based on the determination result of the tank boiling back level, and the night boiling back operation is performed so as to reach the updated tank boiling back level (step 75), and the hot water storage temperature and the hot water storage amount are updated. After reaching the tank boiling back level, the night tank boiling return operation is terminated (step 76). That is, the tank boiling back level is updated on the basis of the number of times of tank boiling back every day, and the nighttime forced tank boiling back operation is performed once a day corresponding to the hot water use situation.

  Next, the tank boiling back operation will be described more specifically with reference to FIG. FIG. 3 is a diagram showing a setting example of a tank boiling back level used for control of the heat pump water heater of FIG.

  The control means 50 sets a plurality of tank boilback levels that combine the boilback amount of the hot water tank 16 and the boilback temperature of the hot water tank 16, and tank boilback operation outside the night time zone (daytime tank boilback operation) Change the boilback level based on the number of boilbacks performed (number of boilbacks during the day), and perform the tank boilback operation at night time (night tank boilback operation) based on this changed boilback level To control.

  Further, the control means 50 preferentially increases the boilback level at the boilback level as the number of daytime tank boilback operations is increased, and the boilback level at the boilback level is set to a predetermined amount. When it reaches, it controls to raise the boil-back temperature of the boil-back level.

  Furthermore, the control means 50 controls to forcibly perform the night tank boiling back operation once a day, and raises the boiling back level when the number of daytime tank boiling back operations exceeds a predetermined number. To control.

  The tank boiling back operation described above is performed based on the tank boiling back level shown in FIG. This tank boil-back level is set in eight levels from (0) to (7). Specifically, when the total capacity of the tank is 100L, the boilback amount is divided into 6 stages from 10L to 100L, and the boilback temperature is divided into 3 stages between 65 ° C and 90 ° C. It is an example of the tank boiling back level which combined return temperature. Accordingly, the tank boiling back level is the lowest level where the level (0) has the least amount of boil-back heat, and the level (7) is the highest level where the amount of the boil-back heat is highest. For each level, the thermistor position, the tank capacity, the target value of the outlet temperature of the water / refrigerant heat exchanger 2 at the time of boiling back, the boiling back start temperature, and the boiling back end temperature are individually defined.

  In addition, as shown in the “outside air temperature (° C.) and initial setting level” column of FIG. 3, the initial setting level is set such that the higher the outside temperature, the lower the tank boiling back level, and the lower the outside temperature, the higher the tank boiling back level. Is done. That is, level (1) is set when the outside air temperature is 20 ° C. or higher, level (3) is set when the outside air temperature is less than 10 to 20 ° C., and the outside temperature is less than 5 to 10 ° C. Is set to level (5), and level (1) is set when the outside air temperature is less than 5 ° C.

  The tank boil-back level is changed based on the number of tank boil-back times per day. Here, the time zone other than the night time zone is divided into a peak time zone and other time zones, the number of boilbacks in the peak time zone is set to n, and the number of boilbacks in the other time zones is set to m.

  The control means 50 is a level obtained by adding (n × 2 + m) to the previous boil-back level when the number of boil-up times during the day is (n + m) ≧ 1 Control to pull up. For example, after performing the boil-back operation at night at level (3) in FIG. 3, when the boil-up operation is performed once in the peak time zone with a large amount of hot water supply, (n + m) = 1, (n × 2 + m) = 2 and the forced boilback level that night is raised by two levels (5), and is raised by two steps. Therefore, the night boil-back operation of the day is performed so as to achieve level (5).

  The control means 50 has a state where the number of remaining hot water in the nighttime tank boilback operation is equal to or greater than a predetermined amount when the number of times of boilback during the day is (n + m) = 0 and continues for a predetermined number of times (for example, three times or more). In such a case, control is performed so that the tank boiling back level of the tank boiling back operation in the next night time zone is lowered by a predetermined level (for example, one level).

  According to this embodiment, it is possible to perform detailed tank boiling back corresponding to diversification of the amount of hot water used, and it is possible to achieve power saving effect by optimizing the tank boiling back amount and temperature, minimizing the number of times of tank boiling back, etc. Obtainable.

  In the above-described embodiment, the case of the instantaneous heat pump water heater has been described. However, the tank boiling back control of the present embodiment can be applied to the hot water heat pump water heater, and the hot water temperature and the amount of hot water are optimized. As a result, it is possible to obtain the effect of preventing hot water burnout during the day and the effect of suppressing the amount of heat released from the large-capacity hot water storage tank.

1 is an overall configuration diagram of a heat pump water heater according to an embodiment of the present invention. It is a flowchart figure which shows the hot water supply operation at the time of opening the kitchen faucet of the heat pump water heater of FIG. 1, and using a hot water, and subsequent tank boiling-back operation. It is a figure which shows the example of a setting of the tank boiling-back level used for control of the heat pump water heater of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1a, 1b ... Compressor, 2 ... Water refrigerant | coolant heat exchanger (1st heat exchanger), 3a, 3b ... Depressurizer, 4a, 4b ... Air refrigerant | coolant heat exchanger (2nd heat exchanger), 6 ... Feed water connection 7 ... Pressure reducing valve, 8 ... Water quantity sensor for water supply, 11 ... Hot water mixing valve, 12 ... Hot water mixing valve, 13 ... Flow rate adjusting valve, 14 ... Kitchen outlet connection port, 15 ... Kitchen faucet, 16 ... Hot water storage tank, 17 ... in-machine circulation pump, 20 ... bath circulation pump, 23 ... bath heat exchanger, 24 ... bathtub, 27 ... bath faucet, 30 ... heat pump circuit, 30a ... first refrigerant circuit, 30b ... second refrigerant circuit, 40 ... hot water supply Circuit, 50 ... control means, 51 ... kitchen remote control, 52 ... bathroom remote control.

Claims (9)

A compressor for compressing the refrigerant;
A first heat exchanger for exchanging heat between the refrigerant discharged from the compressor and water;
A decompression device for decompressing the refrigerant from the first heat exchanger;
A second heat exchanger provided between the decompressor and the compressor;
A hot water storage tank for storing water warmed by the first heat exchanger;
A hot water storage circuit for returning water in the hot water storage tank to the hot water storage tank via the first heat exchanger;
A tank hot water supply circuit for supplying hot water in the hot water storage tank to a use terminal;
In a heat pump water heater provided with a control means for controlling to perform a tank boiling back operation by the hot water storage circuit,
The heat pump water heater is characterized in that the control means performs control so as to perform the tank boilback operation by increasing a boilback heat amount when the tank boilback operation reaches a predetermined number of times . A compressor for compressing the refrigerant;
A first heat exchanger for exchanging heat between the refrigerant discharged from the compressor and water;
A decompression device for decompressing the refrigerant from the first heat exchanger;
A second heat exchanger provided between the decompressor and the compressor;
A hot water storage tank for storing water warmed by the first heat exchanger;
A hot water storage circuit for returning water in the hot water storage tank to the hot water storage tank via the first heat exchanger;
A tank hot water supply circuit for supplying hot water in the hot water storage tank to a use terminal;
In a heat pump water heater comprising a control means for performing a tank boiling back operation by the hot water storage circuit during a night time zone and performing a tank boiling back operation outside the night time zone as necessary,
The control means sets a plurality of tank boil-back heat amounts by combining a boil-back amount of the hot water storage tank and a boil-back temperature of the hot water storage tank, and the number of boil-back times when the tank boil-back operation other than the night time zone is performed. The heat pump water heater is controlled to increase the boil-back heat amount when the predetermined number of times is reached and to perform the tank boil-back operation in the night time zone based on the changed boil-back heat amount . 3. The control unit according to claim 2, wherein the control means preferentially increases the boil back amount of the boil back heat amount with an increase in the number of times of performing the tank boil back operation other than the night time zone, and the boil back heat amount. A heat pump water heater characterized by raising the boiling back temperature of the boil back heat amount when the boil back amount reaches a predetermined amount. 3. The control means according to claim 2, wherein the control means performs control so as to forcibly perform the tank boiling back operation once a day during the night time zone, and the number of times of tank boiling back operation outside the night time zone exceeds a predetermined number. A heat pump water heater that raises the boil-back heat amount when it becomes. 5. The control unit according to claim 4, wherein the control means divides the time zone other than the night time zone into a peak time zone and other time zones, sets the number of times of boil-back in the peak time zone as n, and boiles in the other time zones. The number of times of return is set to m, and when the number of times of re-boiling other than the night time zone is (n + m) ≧ 1, the boil-back heat amount of the tank night-time rebirth operation in the next night time zone is set to the previous boil-back heat amount (n × 2. Heat pump water heater characterized by raising to a level added with 2 + m). 3. The control means according to claim 2, wherein the control means performs control so as to forcibly perform the tank boiling back operation once a day during the night time zone, and a tank remaining hot water amount during the tank boiling back operation during the night time zone is a predetermined amount. A heat pump water heater characterized by lowering the amount of tank boiling back heat in the tank boiling back operation in the next night time zone when the above state continues for a predetermined number of times. 7. The control means according to claim 6, wherein the control means divides the time zone other than the night time zone into a peak time zone and other time zones, sets the number of times of boil-back in the peak time zone as n, and boiles in the other time zones. The number of times of return is set to m, and the state where the amount of remaining hot water in the tank at the time of tank boiling return operation in the night time zone is greater than or equal to a predetermined amount when the number of times of boil back outside the night time zone is (n + m) = 0 A heat pump water heater characterized by lowering the amount of heat of tank boiling back in the tank boiling back operation at the next night time by one level when the number of times is continuous. A compressor for compressing the refrigerant;
A first heat exchanger for exchanging heat between the refrigerant discharged from the compressor and water;
A decompression device for decompressing the refrigerant from the first heat exchanger;
A second heat exchanger provided between the decompressor and the compressor;
A hot water storage tank for storing water warmed by the first heat exchanger;
A hot water storage circuit for returning water in the hot water storage tank to the hot water storage tank via the first heat exchanger;
A direct hot water supply circuit for directly supplying hot water to the use terminal with water heated by the first heat exchanger;
A tank hot water supply circuit for supplying hot water in the hot water storage tank to a use terminal;
In a heat pump water heater comprising a control means for performing a tank boiling back operation by the hot water storage circuit during a night time zone and performing a tank boiling back operation outside the night time zone as necessary,
The control means sets a plurality of tank boil-back heat amounts by combining a boil-back amount of the hot water storage tank and a boil-back temperature of the hot water storage tank, and the number of boil-back times when the tank boil-back operation other than the night time zone is performed. The heat pump water heater is controlled to increase the boil-back heat amount when the predetermined number of times is reached and to perform the tank boil-back operation in the night time zone based on the changed boil-back heat amount .   9. The heat pump water heater according to claim 8, wherein the control means controls to use the direct hot water supply circuit and the tank hot water supply circuit to supply hot water to the use terminal at the start of operation of the heat pump circuit.

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